Electrode material based on a novel core–shell structure consisting of NiCoS（NCS） solid fiber core and Mn S（MS） sheet shell（NCS@MS） in situ grown on carbon cloth（CC） has been successfully prepared by a simple...Electrode material based on a novel core–shell structure consisting of NiCoS（NCS） solid fiber core and Mn S（MS） sheet shell（NCS@MS） in situ grown on carbon cloth（CC） has been successfully prepared by a simple sulfurization-assisted hydrothermal method for high performance supercapacitor. The synthesized NiCoS@Mn S/CC electrode shows high capacitance of 1908.3 F gat a current density of 0.5 A gwhich is higher than those of NiCoSand Mn S at the same current density. A flexible all-solid-state asymmetric supercapacitor（ASC） is constructed by using NiCoS@Mn S/CC as positive electrode, active carbon/CC as negative electrode and KOH/poly（vinyl alcohol）(PVA) as electrolyte. The optimized ASC shows a maximum energy density of 23.3 Wh kgat 1 A g, a maximum power density of about7.5 kw kgat 10 A gand remarkable cycling stability. After 9000 cycles, the ASC still exhibited67.8% retention rate and largely unchanged charge/discharge curves. The excellent electrochemical properties are resulted from the novel core–shell structure of the NiCoS@Mn S/CC electrode, which possesses both high surface area for Faraday redox reaction and superior kinetics of charge transport. The NiCoS@Mn S/CC electrode shows a promising potential for energy storage applications in the future.展开更多
Na^(+)batteries(SIBs)have been emerging as the most promising candidate for the next generation of secondary batteries.However,the development of high-performance and cost-effective anode materials is urgently needed ...Na^(+)batteries(SIBs)have been emerging as the most promising candidate for the next generation of secondary batteries.However,the development of high-performance and cost-effective anode materials is urgently needed for the large-scale applications of SIBs.In this study,carbon dots confined bimetallic sulfide(NiCO_(2)S_(4))architecture(NiCO_(2)S_(4)@CDs)was proposed and synthesized from assembling nanosheets into cross-stacked superstructure and the subsequent confinement of carbon dots.This novel decussated structure assembly from nanosheets is greatly beneficial to the structure stability of electrode material during the successive charge/discharge processes.Besides,the CDs based carbon conductive network can enhance the electrical conductivity for facilitating the easy transport of electron/Na^(+).Benefitting from these advantages,NiCO_(2)S_(4)@CDs exhibits high-rate performance and an ultralong cycling life in SIBs.Specifically,the specific capacity of NiCO_(2)S_(4)@CDs can reach the discharge specific capacity as high as 568.9 mAh/g at 0.5 A/g,which can also maintain 302.7 m Ah/g after 750 cycles at 5.0 A/g.Additionally,ex-situ characterization techniques such as ex-situ XRD and ex-situ XPS were employed to further explore the sodium storage mechanism of the NiCO_(2)S_(4)@CDs anode.展开更多
基金supported by the Grant-in-Aid for Scientific Research (KAKENHI) program, Japan (C, Grant Number 15K05597)Takahashi Industrial and Economic Research Foundation (Takahashi Grant Number 06-003-154)
文摘Electrode material based on a novel core–shell structure consisting of NiCoS（NCS） solid fiber core and Mn S（MS） sheet shell（NCS@MS） in situ grown on carbon cloth（CC） has been successfully prepared by a simple sulfurization-assisted hydrothermal method for high performance supercapacitor. The synthesized NiCoS@Mn S/CC electrode shows high capacitance of 1908.3 F gat a current density of 0.5 A gwhich is higher than those of NiCoSand Mn S at the same current density. A flexible all-solid-state asymmetric supercapacitor（ASC） is constructed by using NiCoS@Mn S/CC as positive electrode, active carbon/CC as negative electrode and KOH/poly（vinyl alcohol）(PVA) as electrolyte. The optimized ASC shows a maximum energy density of 23.3 Wh kgat 1 A g, a maximum power density of about7.5 kw kgat 10 A gand remarkable cycling stability. After 9000 cycles, the ASC still exhibited67.8% retention rate and largely unchanged charge/discharge curves. The excellent electrochemical properties are resulted from the novel core–shell structure of the NiCoS@Mn S/CC electrode, which possesses both high surface area for Faraday redox reaction and superior kinetics of charge transport. The NiCoS@Mn S/CC electrode shows a promising potential for energy storage applications in the future.
基金supported by National Natural Science Foundation of China(No.52101243)Natural Science Foundation of Guangdong Province(No.2023A1515012619)the Science and Technology Planning Project of Guangzhou(No.202201010565)。
文摘Na^(+)batteries(SIBs)have been emerging as the most promising candidate for the next generation of secondary batteries.However,the development of high-performance and cost-effective anode materials is urgently needed for the large-scale applications of SIBs.In this study,carbon dots confined bimetallic sulfide(NiCO_(2)S_(4))architecture(NiCO_(2)S_(4)@CDs)was proposed and synthesized from assembling nanosheets into cross-stacked superstructure and the subsequent confinement of carbon dots.This novel decussated structure assembly from nanosheets is greatly beneficial to the structure stability of electrode material during the successive charge/discharge processes.Besides,the CDs based carbon conductive network can enhance the electrical conductivity for facilitating the easy transport of electron/Na^(+).Benefitting from these advantages,NiCO_(2)S_(4)@CDs exhibits high-rate performance and an ultralong cycling life in SIBs.Specifically,the specific capacity of NiCO_(2)S_(4)@CDs can reach the discharge specific capacity as high as 568.9 mAh/g at 0.5 A/g,which can also maintain 302.7 m Ah/g after 750 cycles at 5.0 A/g.Additionally,ex-situ characterization techniques such as ex-situ XRD and ex-situ XPS were employed to further explore the sodium storage mechanism of the NiCO_(2)S_(4)@CDs anode.
